Alert archive / South Carolina / Mesoscale Discussions in 2017

Mesoscale Discussion 887

May 27, 20176 counties in Georgia; 16 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at May 27, 2017, 11:16 PM EDT for 6 counties in Georgia; 16 counties in South Carolina. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued: May 27, 2017, 11:16 PM EDT (03:16 UTC)
Expired: May 28, 2017, 12:45 AM EDT
In force: 89 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

All 22 counties

Elbert County, GA, Franklin County, GA, Habersham County, GA, Hart County, GA, Rabun County, GA, Stephens County, GA, Abbeville County, SC, Anderson County, SC, Cherokee County, SC, Chester County, SC, Fairfield County, SC, Greenville County, SC, Greenwood County, SC, Laurens County, SC, McCormick County, SC, Newberry County, SC, Oconee County, SC, Pickens County, SC, Saluda County, SC, Spartanburg County, SC, Union County, SC, York County, SC

The radar

The Greer radar (KGSP), 37 km from the middle of the area, began a volume at 03:17 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 288May 28, 12:10 AM EDT

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 3.3 hours before the alert went out and 242 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 930 J/kg
Mixed-layer CIN: -238 J/kg
Mixed-layer LCL: 1118 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 103 m²/s²
0-3 km storm-relative helicity: 173 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.8

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 27, 10:07 PM EDT	Severe Thunderstorm Watch	SPC	Banks, Bartow, Catoosa, Chattooga, Cherokee, Dade and 17 more	8 hr
May 28, 12:13 AM EDT	Severe Thunderstorm Watch	SPC	Elbert, Franklin, Habersham, Hart, Rabun, Stephens	3 hr
May 28, 3:11 AM EDT	Mesoscale Discussion	SPC	Carroll, Floyd, Haralson, Heard, Polk	2 hr
May 28, 3:53 AM EDT	Severe Thunderstorm Watch	SPC	Butts, Carroll, Clayton, Cobb, Coweta, DeKalb and 16 more	4 hr
May 28, 6:29 AM EDT	Mesoscale Discussion	SPC	Baldwin, Bibb, Butts, Clayton, Cobb, Coweta and 21 more	2 hr
May 28, 4:56 PM EDT	Mesoscale Discussion	SPC	Calhoun, Chesterfield, Clarendon, Darlington, Dillon, Fairfield and 11 more	2 hr
May 28, 7:06 PM EDT	Severe Thunderstorm Watch	SPC	Berkeley, Calhoun, Charleston, Clarendon, Darlington, Dillon and 11 more	4 hr

Nearby

Mesoscale Discussions in South Carolina, 2017 Mesoscale Discussions in Georgia, 2017 Every mesoscale discussion in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.